Provided is a fluid-cooled melting tool that can be used in methods and systems for manufacturing objects by additive manufacturing techniques, especially titanium and titanium alloy objects. In some configurations, the melting tool is configured to be a plasma transferred arc (PTA) torch and the deposition rate can be increased by increasing the flow rate of electric charge through the electrode made possible by the dual circuit cooling design of the torch. The fluid-cooled melting tools provided herein exhibit stable and repeatable PTA characteristics over wide range of current including current of 400 amps or more, whether pulsed or non-pulsed, and plasma gas flow inputs.

Provided is a fluid-cooled melting tool that can be used in methods and systems for manufacturing objects by additive manufacturing techniques, especially titanium and titanium alloy objects. In some configurations, the melting tool is configured to be a plasma transferred arc (PTA) torch and the deposition rate can be increased by increasing the flow rate of electric charge through the electrode made possible by the dual circuit cooling design of the torch. The fluid-cooled melting tools provided herein exhibit stable and repeatable PTA characteristics over wide range of current including current of 400 amps or more, whether pulsed or non-pulsed, and plasma gas flow inputs.

A consumable assembly for a plasma arc torch is provided, the consumable assembly including an electrode provided within an interior of a nozzle. The electrode may include a sidewall having one or more fluid passageways formed therethrough, an end wall extending from a distal end of the sidewall, and a central cavity defined by an inner surface of the sidewall and the end wall, the central cavity extending between distal and proximal ends of the electrode. The electrode may further include a heat removal element extending into the central cavity from the inner surface of the sidewall. In one embodiment, the consumable assembly includes a current and gas conduit at the proximal end of the electrode, the current and gas conduit including an interior bore radially aligned with the electrode for collectively delivering a plasma gas, a shield gas, and a vent gas into the central cavity of the electrode.

A consumable assembly for a plasma arc torch is provided, the consumable assembly including an electrode provided within an interior of a nozzle. The electrode may include a sidewall having one or more fluid passageways formed therethrough, an end wall extending from a distal end of the sidewall, and a central cavity defined by an inner surface of the sidewall and the end wall, the central cavity extending between distal and proximal ends of the electrode. The electrode may further include a heat removal element extending into the central cavity from the inner surface of the sidewall. In one embodiment, the consumable assembly includes a current and gas conduit at the proximal end of the electrode, the current and gas conduit including an interior bore radially aligned with the electrode for collectively delivering a plasma gas, a shield gas, and a vent gas into the central cavity of the electrode.

Plasma spray apparatus for coating substrates, including at least a working chamber including a plasma torch and at least a substrate support, in which an inert gas or a mixture of inert gases is contained at a pressure which is close to the normal pressure, and at least a gas circuit, in communication with said working chamber, including recirculating means of the inert gases contained in said working chamber. The recirculating means include a closed loop, including a blower and a first heat exchanger communicating with said working chamber for extracting the inert gases and supplying a first fraction of the cooled inert gases back into a first portion of the working chamber, and at least a path, communicating with said closed loop and including a compressor and a second heat exchanger for supplying a second fraction of the cooled inert gases into a second portion of the working chamber.

Plasma spray apparatus for coating substrates, including at least a working chamber including a plasma torch and at least a substrate support, in which an inert gas or a mixture of inert gases is contained at a pressure which is close to the normal pressure, and at least a gas circuit, in communication with said working chamber, including recirculating means of the inert gases contained in said working chamber. The recirculating means include a closed loop, including a blower and a first heat exchanger communicating with said working chamber for extracting the inert gases and supplying a first fraction of the cooled inert gases back into a first portion of the working chamber, and at least a path, communicating with said closed loop and including a compressor and a second heat exchanger for supplying a second fraction of the cooled inert gases into a second portion of the working chamber.

A method for plasma coating an object includes an object profile, having the steps of: a) manufacturing a replaceable shield comprising a jet inlet, a nozzle outlet and a sidewall extending from the jet inlet to the nozzle outlet, wherein the nozzle outlet includes an edge essentially congruent to at least part of the object profile; b) detachably attaching the replaceable shield to a jet outlet of a plasma jet generator; c) placing the object at the nozzle outlet such that the object profile fits closely to the nozzle outlet edge; d) plasma coating the object with a low-temperature, oxygen-free plasma at an operating pressure which is higher than the atmospheric pressure by providing a plasma jet in the shield via the plasma jet generator and injecting coating precursors in the plasma jet in the shield.

A method for plasma coating an object includes an object profile, having the steps of: a) manufacturing a replaceable shield comprising a jet inlet, a nozzle outlet and a sidewall extending from the jet inlet to the nozzle outlet, wherein the nozzle outlet includes an edge essentially congruent to at least part of the object profile; b) detachably attaching the replaceable shield to a jet outlet of a plasma jet generator; c) placing the object at the nozzle outlet such that the object profile fits closely to the nozzle outlet edge; d) plasma coating the object with a low-temperature, oxygen-free plasma at an operating pressure which is higher than the atmospheric pressure by providing a plasma jet in the shield via the plasma jet generator and injecting coating precursors in the plasma jet in the shield.

Certain configurations are described herein of an instrument comprising a passive cooling device which includes, in part, a loop thermosyphon configured to thermally couple to a component of the instrument to be cooled. In some instances, the cooling device can cool a transistor, transistor pair, an interface or other components of the instrument.

A plasma torch includes a first element provided with a through opening for the exit of a plasma flow, and a hollow electrode which develops longitudinally along a main axis and can be positioned with respect to the first element in such a way as to define a striking area. The hollow electrode includes an inner cavity which extends at least partially along the main axis and a main conveyance way suited to convey a carrier gas. The torch includes a first divider suited to divide the main way into a first conveyance way suited to convey a portion of the carrier gas from the main way towards the striking area and into a second conveyance way suited to convey a portion of the carrier gas from the main way towards the inner cavity of the hollow electrode, the portion of carrier gas of the second way being suited to cool down the hollow electrode, and a second divider arranged downstream of the first divider, suited to divide the first way into a third conveyance way suited to convey a portion of the carrier gas from the first way towards the striking area and into a fourth conveyance way suited to convey a portion of the carrier gas from the first way towards the first element, the portion of carrier gas of the fourth way being suited to cool down the first element.